Tris(2-methyl-2-phenylpropyl)stannane derivatives, (Neo)₃SnX revisited. Comparison of crystal structures of (Neo)₃SnX (X=Cl, Br, I, N₃, NCS and OAc)

The H-1,C-13 and Sn-119 NMR and far-IR spectra of tris(neophyl)stannanes, (PhCMe2CH2)(3)SnX, (Neo)(3)SnX, [1: X = F, Cl, Br, I, N-3, NCS, OSn(Neo)(3) and OAc], and the crystal structures of 1 (X = Br, I, N-3, NCS and OAc) are reported. The compounds 1 (X = B-r,B- I, N-3 and NCS) and the previously reported 1 (X = Cl) all contain four-coordinate tin centers, with distorted tetrahedral geometries in the solid state. In contrast, 1 (X = OAc) is five-coordinate due to the acetate group acting as a chelating ligand. With the exception of 1 (X = Cl), all the compounds have entirely molecular Structures With only van der Waals forces controlling the packing of the molecules. The molecules in 1 (X = Cl), with threefold axial symmetry. are packed head to tail in rows with weak C-H Cl-. . . intermolecular contacts. (C) 2002 Elsevier Science Ltd. All rights reserved.